Vol. 5 Issue 2
Mahmoud H. Abdel-Aziz and Mohammad Saeed
Crop coefficients, with reference to alfalfa, were determined for four vegetable crops which could be used in estimating water requirements under the hot and arid conditions of Saudi Arabia. The vegetable crops and alfalfa were grown in lysimeters and the evapotranspiration (ET) was measured. Crop coefficients were obtained from the data. Coefficients, with respect to evaporation from class A pan and Piche evaporimeter were also obtained, which could be used by farmers and irrigationist to estimate water requirements.
The crop coefficients varied at various stages of growth, and hence a single crop coefficient value is not suitable for ET estimation of the crop cycle. The coefficients differed from those obtained by research scientists at other places, under different environmental conditions, suggesting that the coefficients given here are more suitable for ET estimation, under the hot and arid climate of Saudi Arabia.
A.S.H. Kansouh, M.S. Abdel Fattah and M.M. Hosny
The susceptibility to 3 insecticides of the 4th instar S. littoralis larvae was measured topically for the 1st generation produced from samples of the 5th and 6th instar larvae collected from the field before and after spraying of each insecticide, in two successive seasons. The single application of Endrin or the successive insecticidal rotations ending with Endrin, increased the tolerance to Endrin, while there was no tolerance to either Cytrolane or Lannate. The single application of Cytrolane or the successive insecticidal rotations ending with Cytrolane, did not cause tolerance to Cytrolane or Lannate; and the same trend was obtained for the use of Lannate or the successive insecticidal rotations ending with Lannate. Meanwhile, the susceptibility of these strains of Endrin varied in the two successive cotton seasons.
The susceptibility of the 4th instar S. littoralis larvae was also studied in the laboratory with the same pattern of rotations followed in the field. The data obtained showed almost the same trend of field results, after successive treatments in three successive generations. Apparently, it is advisable not to apply one insecticide (Endrin) successively within one season.
Y.M. Makki, H.O. Burhan, O.A. Al-Tahir and A.I. Mustafa
Agronomic research on wheat (Triticum aestivum L.) in the eastern region of Saudi Arabia is limited. Field experiments were conducted in Al-Hassa area to study the effects of planting date and nitrogen fertilizer on the growth and yield of the wheat variety Arz. Treatments included early and late November and early and Late December, and three fertilizer nitrogen levels, 40, 80 and 120 kgN/ha. Final plant height and weight increased with early sowing and higher fertilizer levels. Flag leaf area and concentration of chlorophyll in the leaves were indicators of higher photosynthetic activity. Grain yield increased significantly as the level of fertilizer nitrogen increased, and decreased as sowing was delayed. The number of kernels per spike was increased by nitrogen in both seasons and by early sowing in the second seasons. Kernel weight significantly increased with early sowing. It was concluded that early November is the optimum sowing date and nitrogen levels of 120 kg/ha or more result in high yields.
H. Al-Kady, A. Badawi and A.A. Faragalla
Based on the morphological characters of worker and soldier mandibular dentition and wing venation of alate forms, differentiation was made among 11 species of termites commonly found in Saudi Arabia: Anacanthotermes ochraceus (Burm.), A. ubachi (Navas), A. vagans (Hagen), Psammotermes hybostoma Desneux, Microcerotermes gabrielis Weidner, M. parvulus (Sjostedt), Amitermes messinae Fuller, A. vilis (Sands), Eremotermes sabaeus Harris, Microtermes najdensis Harris and M. yemenensis Wood.
Ali El-Toum Hassan
Three corn cultivars (Zea Mays L.) were planted at different population densities and examined for number of days to mid-silk, plant height, and grain yield. Both plant height and grain yield differed between the two years. The local cultivar reached the mid-silk stage later and out yielded the other two cron cultivars. Grain yield was found to increase with population density. These results suggest that additional research should be conducted with population densities above 50,000 plants per hectare.
Samir M. Khoja
The regulatory properties of mouse jejunal mucosa phosphofructokinase have been studied in crude extracts freed from low molecular weight effectors on Sephadex G-100, and compared to those of the rat. Both isoenzymes displayed cooperativity with respect to fructose 6-phosphate at pH 7.0 in the presence of inhibitory concentrations of ATP. The rat isoenzyme was activated to a greater extent by AMP and P1 and inhibited to a greater extent by creatine phosphate than the mouse isoenzyme. Bothe isoenzymes were strongly activated by glucose 1,6-bisphosphate and strongly inhibited by citrate. The general similarity in properties of the two isoenzymes reflects the fact that both rat and mouse intestinal mucosa are characterised by high rates of aerobic glycolysis.
M.M. Dorgham, A. Muftah and K.Z. El-Deeb
The study area extends along the northwestern part of the Arabian Gulf off Kuwaiti, Saudi and Qatari shores. The species composition and biomass of the phytoplankton in addition to the physical and chemical factors of the Gulf water were followed horizontally and vertically during Nov. 1984.
The most characteristic features of the water were the significant low nitrate-phosphate ratio, lack of nutrient balance, and detected high level of oil pollution in some positions. The phytoplankton population was characterized by great diversity of species (223 taxa) and low standing crop. Tight relationship was observed between the physico-chemical parameters and oil pollution in the area, and the diversity of species and biomass of phytoplankton. The studied environmental factors showed variations in the different regions of the investigated area, which were reflected on the phytoplankton population in each region.
Mahmud J. Abussaud and Mamdoh M. Magdam
In vitro susceptibility testing of bacteria isolated from infected wounds from different sources in Basma Hospital, Irbid, demonstrated that all gram-negative bacteria were resistant to novobiocin and sensitive to gentamycin. Staphylococcus aureus strains isolated from infected wounds were mostly either resistant to penicillin G and ampicillin or sensitive to gentamycin. Variable susceptibilities were observed for the tested antibiotics. As the differences between the resistant patter of S. Aureus, isolated from different sources, was statistically significant, no single source os S. aureus can be considered to be responsible for the spread of infection. Therefore, the bacteria must have been originated from multiple sources
H.A. Bokhary
Three edible hypogeous fungi were collected and identified. There were Tirmania nivea (Desf. ex Fr. ) Trappe, Tirmania pinoyi (Maire) Malecon, and Terfezia boudieri Chatin. They are recorded, illustrated and described for the first time in Saudi Arabia. Their sites of occurrence, the ecological and biological factors affecting their distribution are discussed.
M.M. El-Naggar and H.M. Serag
A description is given of Macro Gyrodactylus clasrii Gussev 1961, a monogenean from the gills of Clarias lazera inhabiting Nile Delta waters in Egypt. This is the first record of a monogenean of the genus Macrogyrodactylus in Egypt. The gills of C. lazera represents a new microhabitat for M. clarii. Particular attention has been paid to the anatomy of the anterior adhesive apparatus, digestive system, reproductive system and haptoral selerites. A vagina was found to be absent. The possible functions of some internal organs are discussed.